org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators
Class POPartialAgg
java.lang.Object
org.apache.pig.impl.plan.Operator<PhyPlanVisitor>
org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator
org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POPartialAgg
- All Implemented Interfaces:
- Serializable, Cloneable, Comparable<Operator>, Illustrable
public class POPartialAgg
- extends PhysicalOperator
Do partial aggregation in map plan. It uses a hash-map to aggregate. If
consecutive records have same key, it will aggregate those without adding
them to the hash-map. As future optimization, the use of hash-map could be
disabled when input data is sorted on group-by keys
- See Also:
- Serialized Form
Fields inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator |
alias, dummyBag, dummyBool, dummyDBA, dummyDouble, dummyFloat, dummyInt, dummyLong, dummyMap, dummyString, dummyTuple, illustrator, input, inputAttached, inputs, lineageTracer, outputs, parentPlan, pigLogger, reporter, requestedParallelism, res, resultType |
Fields inherited from class org.apache.pig.impl.plan.Operator |
mKey |
Methods inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator |
attachInput, clone, cloneHelper, detachInput, getAlias, getAliasString, getDummy, getIllustrator, getInputs, getLogger, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getPigLogger, getRequestedParallelism, getResultType, isAccumStarted, isAccumulative, isBlocking, isInputAttached, processInput, reset, setAccumEnd, setAccumStart, setAccumulative, setAlias, setIllustrator, setInputs, setParentPlan, setPigLogger, setReporter, setRequestedParallelism, setResultType |
PROP_PARTAGG_MINREDUCTION
public static final String PROP_PARTAGG_MINREDUCTION
- See Also:
- Constant Field Values
POPartialAgg
public POPartialAgg(OperatorKey k)
illustratorMarkup
public Tuple illustratorMarkup(Object in,
Object out,
int eqClassIndex)
- Description copied from interface:
Illustrable
- input tuple mark up to be illustrate-able
- Parameters:
in
- input tupleout
- output tuple before wrapped in ExampleTupleeqClassIndex
- index into equivalence classes in illustrator
- Returns:
- tuple
visit
public void visit(PhyPlanVisitor v)
throws VisitorException
- Description copied from class:
Operator
- Visit this node with the provided visitor. This should only be called by
the visitor class itself, never directly.
- Specified by:
visit
in class PhysicalOperator
- Parameters:
v
- Visitor to visit with.
- Throws:
VisitorException
- if the visitor has a problem.
getNext
public Result getNext(Tuple t)
throws ExecException
- Overrides:
getNext
in class PhysicalOperator
- Throws:
ExecException
supportsMultipleInputs
public boolean supportsMultipleInputs()
- Description copied from class:
Operator
- Indicates whether this operator supports multiple inputs.
- Specified by:
supportsMultipleInputs
in class Operator<PhyPlanVisitor>
- Returns:
- true if it does, otherwise false.
supportsMultipleOutputs
public boolean supportsMultipleOutputs()
- Description copied from class:
Operator
- Indicates whether this operator supports multiple outputs.
- Specified by:
supportsMultipleOutputs
in class Operator<PhyPlanVisitor>
- Returns:
- true if it does, otherwise false.
name
public String name()
- Specified by:
name
in class Operator<PhyPlanVisitor>
getKeyPlan
public PhysicalPlan getKeyPlan()
setKeyPlan
public void setKeyPlan(PhysicalPlan keyPlan)
getValuePlans
public List<PhysicalPlan> getValuePlans()
setValuePlans
public void setValuePlans(List<PhysicalPlan> valuePlans)
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